报纸中谈到关于鲸鱼搁浅
On average, 8 humpback whales are stranded each year from Maine to
Virginia, and fewer than 2 are hit by ships, according to data from
NOAA.
An unusual mortality event is a specific designation under the Marine
Mammal Protection Act, and is defined as "a stranding that is unexpected,
involves a significant die-off of any marine mamal population, and
demands immediate response."
请问第二段第一行的designation在这里要怎么理解比较好呢？
另外，有篇文章提到川普与习近平
The end of the honeymoon does not mean that China and America are at
daggers drawn. A recent phone call between the presidents suggests
they are still prepared to work together on North Korea. But the
timing of America's China-riling moves was significant.
rife原意是“激怒”，China-riling在这里意思是什么呢？
拜托大家了!